Acquiring token using client certificate

Program.cs

using System;
using System.Security.Cryptography.X509Certificates;
using Microsoft.IdentityModel.Clients.ActiveDirectory;
 
namespace SignedJwt
{
  class Program
  {
    static void Main(string[] args)
    {
      string adfsInstance = "https://contoso.com/adfs/";
      string ResourceId = "https://contoso.com/api";
      string clientId = "copy-from-adfs-server";
      string clientSecret = "copy-from-adfs-server";            
             
      ClientAssertionCertificate certCred = null;
      AuthenticationContext authContext = null;            
      var authority = $"{adfsInstance}";
 
      authContext = new AuthenticationContext(authority, false);
 
      X509Certificate2 cert = new X509Certificate2("adfs.contoso.com.pfx");
 
      var token = "";
      AuthenticationResult result = null;
      try
      {                
        ClientCredential clientCred = new ClientCredential(clientId, clientSecret);
        certCred = new ClientAssertionCertificate(clientId, cert);                
        result = authContext.AcquireTokenAsync(ResourceId, certCred).Result;
        token = result.AccessToken;
      }
      catch (Exception x)
      {               
        Console.WriteLine($"Error: {x.Message}");                               
      }
      Console.WriteLine($"Token: {token}");
    }
  }
}